1. Field of the Invention
This invention relates generally to packaging apparatus, and more particularly to an adjustable guide roller for installation on the tube shaping former of form-fill-seal packaging apparatus to provide proper positioning and tension of the material as it passes over the former and which allows easy removal of the former from the packaging apparatus.
2. Brief Description of the Prior Art
Packing machines of the so-called vertical form-fill-seal class are known in the art. Machines of this type guide a web of flexible packaging material from a supply roll of the material over a forming hood commonly known as a "former", where it is formed into an open ended tubing tubular configuration, intermittently fed downward, sealed to form a longitudinal tube seam, filled with a product, and ultimately sealed at package length intervals and cut into individual packages.
The "former" surrounds the upper portion of a fill pipe, and a dosing device cooperates with the mouth of the fill pipe for gravity feeding the material to be packaged into the fill pipe.
Most machines of the above described type incorporate a guide roller which is fixed to the machine frame or to the plate which supports the "former." Replacing or removing the fixed roller assemblies from the machine is time consuming and costly because it is necessary to unbolt and raise the dosing device above the top of the former and then lift the former assembly up and forwardly out of the machine so that the fixed roller assembly will clear the machine framework.
There are several patents which disclose packaging machines with various fixed guide roller assemblies.
Dreeben, U.S. Pat. No. 2,955,398 discloses a packaging machine feed mechanism particularly suited to accommodate highly elongatable materials such as polyethylene. The mechanism comprises a slack controller interposed between the web roll and the forming tube. The slack controller includes a spring biased brake arm carried on a pivot pin supported by the machine frame which controls the withdrawal the material from the web roll in timed sequence with the reciprocating gripping jaws which pull the packaging material over the forming tube. A guide roller is mounted on a carriage carried by the frame of the machine.
Wilson, U.S. Pat. No. 3,415,171 discloses a package forming machine having a split tube former which is laterally expandable. The strip of packaging material is fed past a series of guide rollers and is directed somewhat laterally over a guide shoulder portion of the former.
Leasure, U.S. Pat. No. 3,027,695 discloses a packaging apparatus having a vertically reciprocating former and a roller member under which the strip of packaging material passes and which is movable with the reciprocating former.
Lasko, U.S. Pat. No. 2,113,658 discloses a packaging machine in which the sheet of packaging material is delivered from the supply roll over a guide roller and between a pair of gear driven feed rolls after which it is guided over a triangular apron. The guide roller is connected to the framework of the machine and may be adjusted so that the sheet will properly enter between the two feed rolls.
The present invention is distinguished over the prior art in general, and these patents in particular by the provision of an adjustable guide roller assembly installed on the tube forming apparatus of form, fill and seal packaging machines which have a depending tubular fill pipe through which quantities of product are passed and over which a strip of packaging material is pulled to progressively form the material into a depending and upwardly open tubular configuration and subsequently sealed to form product bearing packages. The adjustable guide roller assembly is removably mounted on the back of the tube former adjacent the curved shaping portion which receives the strip material and is pivotally and horizontally movable relative thereto to receive and adjustably position the strip material thereon. The guide roller member of the assembly is capable of being pivotally raised above the top of the lowermost surface of the shaping portion of the former to clear the machine framework supporting the former allowing it to be removed horizontally outward from the packaging machine.